|Last summer I lost most of my petunias, marigolds and other annuals to bugs flying around the soil and plants. I just noticed them again in some of my pots. Do these live in the soil or come on the plants when I purchase? Do I need to discard the dirt, wash the roots and replant or is there something I can use to treat them without throwing out all the dirt?
|Unfortunately, based on your description I am not certain which insects would have damaged your plants. Without knowing more specifically what it is, it is very difficult to give you recommendations. Not all controls will work on all pests, so you need to identify the pest first, then decide how to treat it.
However, it might have been Japanese beetles; these are metallic colored beetles that fly, they land on plants and will damage flowers and leaves. They are difficult to control because they are so widespread. They can be handpicked and dropped into soapy water, if there are just a few. Sometimes spraying with a product containing neem will repel them. They can also be treated with carbaryl (the active ingredient in Sevin, for example) although this is a contact insecticide so it must contact the pest to kill it.
You might also want to consult with your local Rutgers county extension to obtain a more specific identification of the pest and based on knowing that, decide what to do. If a chemical control is needed, they will have the most up to date recommendations on what to use and how/when is best to apply it for maximum results.